A Swedish mega-study that tracked five million people over a fifty year period has all but verified earlier research that found links between physical height and cancer. Conducted by Stockholm's Karolinska Institute, the study found that for every four inches above average height, the risk of any cancer rises by 18 percent for women and 11 percent for men. Women who are taller than the norm are 20 percent more liable to develop breast cancer, while taller individuals of both sexes have a 30 percent higher rate of skin cancer. The researchers note that the link is statistical, not causal, and may be the result of different growth factors at play during adolescence or simply due to the fact that taller peoples' greater size means they have more cells that may become cancerous.